The U.S. military says an attacker wearing an Iraqi army uniform shot and killed two American soldiers in northern Iraq Saturday.

Military officials say three other U.S. soldiers were wounded in the attack at a combat outpost 20 kilometers south of Mosul.

The military says the attacker was also killed.

Elsewhere in northern Iraq, Iraqi police say a roadside bomb blast killed three workers and wounded two others near Kirkuk.  A police official, Brigadier General Sarhad Qadir, says the explosion struck the workers' vehicle Saturday as it was traveling south of Kirkuk.

Separately, police say a would-be suicide bomber arrested Friday at the gate of a Shi'ite mosque in Kirkuk has been identified as a Syrian linked to al-Qaida in Iraq.

Kirkuk's police chief, Major General Torhan Yussef, says Ammar Afif Hamada confessed to his participation in al-Qaida operations in Iraq.

Guards stopped Hamada, who was wearing an explosives belt, as he tried to enter the mosque.  Reports say he began shooting before being wrestled to the ground.

The oil-rich Kirkuk region is at the center of a power struggle between ethnic and religious groups including Kurds, Arabs, Turks and Christians. 

Some information for this report was provided by AFP, AP and Reuters.